Difluorocarbene generated from FSO2CF2CO2SiMe3 (TFDA) at 120 degrees C could reacted with terminal alkynes having an ester group at the a position to the triple bond. Difluorocyclopropenes were further converted to difluorocyclopropyl ketones under alkaline condition. Mechanism for the conversion was studied. (C) 2009 Elsevier Ltd. All rights reserved.